The biggest demolition job in quake-hit Christchurch will begin today.

The PricewaterhouseCoopers building was badly damaged in last year's devastating February earthquake and it was not feasible to repair it, the Canterbury Earthquake Recovery Authority said in a statement.

At 21 storeys it was not Christchurch's tallest building but it was its largest by land mass.

The demolition job, being carried out by Arrow International, Nikau and Coleman and Company (UK), is expected to take 40 weeks to complete.


The top third of the building is to be demolished using the "cut-and-crane method" while the last 14 floors will be dismantled using a high-reach crane known as Twinkletoes.

The first stages of the demolition will involve stripping out the 21 floors, and it will be some weeks before the demolition proper begins.